Heat pipe auxiliary cooling device for graphitization furnace, graphitization furnace and method

Abstract

The present invention relates to the field of graphitization furnace cooling technology, and specifically to a heat pipe auxiliary cooling device for a graphitization furnace, a graphitization furnace and a method, which are applied to a graphitization furnace, wherein the graphitization furnace has a heat insulation layer, and the heat pipe auxiliary cooling device comprises: a heat absorption unit, comprising a plurality of heat pipes, and arranged on the heat insulation layer in sequence from the outside to the inside; the working temperatures of the plurality of heat pipes increase in sequence from the outside to the inside; an auxiliary cooling unit, comprising a cooling water device, and one end of the heat absorption unit is connected to the cooling water device. The present invention modularizes the heat pipe cooling auxiliary device, designs the arrangement positions of heat pipes with different working temperatures, and cooperates with the cooling water device to achieve efficient cooling, shorten the cooling time, and solve the problem of thermal stress concentration.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature cooling, and in particular to a heat pipe auxiliary cooling device for a graphitization furnace, a graphitization furnace and a method. Background Art

[0002] Due to its many good properties, graphite is widely used in production and life. However, the graphite formed in nature can no longer meet the market demand due to its long formation process, many components, uneven quality, and the increasing demand for graphite in society. Therefore, the production of industrial graphite has become particularly important. As a key equipment for industrial graphite production, the operating efficiency and cooling technology of the graphitization furnace will directly affect the quality and production cost of the product. Traditional graphitization furnaces generally use natural cooling to cool down. Although this method is simple and easy, it takes a long time and occupies more than 90% of the production cycle, which seriously restricts the improvement of production efficiency. In order to overcome this problem, the industry began to explore more efficient cooling technologies.

[0003] Early cooling module designs, such as waste heat pipe coils, metal straight pipes or serpentine coils, were tried in the cooling system of graphitization furnaces. However, these cooling methods exposed the problem of low cooling efficiency and failure to meet the demand for rapid cooling in actual applications. Especially in high temperature environments above 2700K, the heat dissipation effect of these traditional cooling modules is greatly reduced and cannot meet the production needs of graphitization furnaces.

[0004] In order to further improve the cooling efficiency of the graphitization furnace, heat pipe cooling technology has gradually come into people's view. Heat pipe cooling mainly realizes efficient heat exchange by absorbing or releasing heat when the physical state of the cooling medium changes. However, in the actual application of the graphitization furnace, heat pipe cooling technology also faces many challenges. For example, the prior art 1 with the publication number CN116608698A proposes a heat pipe cooling graphitization furnace, in which a fan is mainly used to cool the high-temperature heat pipe. However, the heat dissipation effect of the fan on the high-temperature heat pipe is limited, and it cannot meet the heat dissipation requirements of high-temperature heat pipes above 2700K.

[0005] In addition, the prior art 2 with the publication number CN219914097U proposes a large temperature difference combined heat pipe for cooling the graphitization furnace. The technical solution is connected into a heat pipe group through a carbon-carbon composite material belt to achieve rapid cooling of the graphitization furnace. However, since the heat pipe will be deeply buried in the graphitization furnace, the application of the carbon-carbon composite material belt will inevitably cause physical damage to the internal structure of the graphitization furnace, thereby affecting the thermal stability of the furnace body. In addition, this technical solution also needs to deal with a key problem in practical applications. The extreme and changeable temperature environment inside the graphitization furnace, especially when the temperature gradient increases sharply, is prone to cause thermal stress concentration. In the long run, it will affect the overall service life of the furnace body, especially after the temperature rises sharply, exceeding the working limit of the heat pipe, which often causes the high-temperature heat pipe such as sodium, potassium and other working fluids to boil, reducing the heat transfer performance of the heat pipe. Summary of the invention

[0006] In order to solve the problem of insufficient heat dissipation efficiency of high-temperature heat pipes by fans and the problem that thermal stress concentration may be aggravated and heat transfer performance of heat pipes may be reduced when carbon-carbon composite material strips are connected into heat pipe groups, the purpose of the present invention is to provide a heat pipe auxiliary cooling device for a graphitization furnace, a graphitization furnace and a method.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows.

[0008] The present invention provides a heat pipe auxiliary cooling device for a graphitization furnace, which is applied to the graphitization furnace. The graphitization furnace has a heat insulation layer. The heat pipe auxiliary cooling device comprises:

[0009] The heat absorption unit includes a plurality of heat pipes, which are arranged on the insulation layer in sequence from the outside to the inside; the plurality of heat pipes are divided into a plurality of heat pipe groups, and the working temperatures of the plurality of heat pipe groups increase in sequence from the outside to the inside; the auxiliary cooling unit includes a cooling water device, and one end of the heat absorption unit is connected to the cooling water device.

[0010] The present invention performs modular design on the heat pipe cooling auxiliary device and designs the arrangement positions of heat pipes with different working temperatures, thereby optimizing the temperature field of the insulation layer to make the temperature distribution uniform, eliminating the thermal stress concentration phenomenon caused by a sharp increase in temperature gradient, and increasing the working temperatures of multiple heat pipes in sequence from the outside to the inside, so that the heat pipes with different working temperatures are matched with the temperature distribution in the corresponding insulation layer, thereby avoiding exceeding the working limit of the heat pipe after a sharp increase in temperature. Therefore, the present invention performs modular design on the heat pipe cooling auxiliary device, thereby avoiding the problem of boiling of the medium in the heat pipe and ensuring the stability of the heat transfer performance of the heat pipe.

[0011] The present invention uses a heat absorption unit in conjunction with a cooling water device to achieve efficient cooling and shorten the cooling time, while solving the problem of insufficient heat dissipation efficiency of the current fan for high-temperature heat pipes and the problem that when the carbon-carbon composite material strips are connected into a heat pipe group, thermal stress concentration may be aggravated, thereby reducing the heat transfer performance of the heat pipe.

[0012] Preferably, the thermal insulation layer forms a plurality of temperature distribution layers along a direction from outside to inside; the plurality of heat pipes are sequentially arranged on the corresponding temperature distribution layers along a direction from outside to inside; and the operating temperatures of the heat pipes on the same temperature distribution layer are all the same.

[0013] The present invention arranges different numbers of heat pipes to adapt to graphitization furnaces of different sizes; according to the temperature distribution of the insulation layer, heat pipes with different working temperatures are arranged on different temperature distribution layers of the insulation layer, which is beneficial to controlling the cooling rate of the graphitization furnace, realizing the control of the uniformity of the internal thermal field of the graphitization furnace, and thus helping to improve the production efficiency of the graphitization furnace.

[0014] Preferably, the plurality of heat pipe groups are respectively recorded as a first heat pipe group, a second heat pipe group and a third heat pipe group, the heat pipes of the first heat pipe group are recorded as first heat pipes, the heat pipes of the second heat pipe group are recorded as second heat pipes, the heat pipes of the third heat pipe group are recorded as third heat pipes, and the first heat pipes, the second heat pipes and the third heat pipes are arranged sequentially on the insulation layer from outside to inside; the operating temperatures of the first heat pipes, the second heat pipes and the third heat pipes increase sequentially.

[0015] In the present invention, the first heat pipe is a low-temperature heat pipe, the second heat pipe is a medium-temperature heat pipe, and the third heat pipe is a high-temperature heat pipe. Among them, the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are located on the side of the insulation layer, at a certain distance from the inner side of the refractory layer. When the graphite block reaches a high temperature of 3000K, the insulation layer stops being energized, and the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe exchange heat with the insulation layer. Heat is transferred from the insulation layer to the evaporation section of the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe, and then to the condensation section of the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe, and finally connected to the cooling water device through the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe, respectively, to transfer heat to the external environment.

[0016] Preferably, the operating temperature of the first heat pipe is 300K~550K, and the first heat pipe is arranged in a temperature distribution layer in the insulation layer with a temperature of ≤600K; the operating temperature of the second heat pipe is 550K~750K, and the second heat pipe is arranged in a temperature distribution layer in the insulation layer with a temperature of 700K~800K; the operating temperature of the third heat pipe is 750K~1200K, and the third heat pipe is arranged in a temperature distribution layer in the insulation layer with a temperature of 1200K~1300K.

[0017] In the present invention, the heat preservation layer is set to form a first temperature distribution layer, a second temperature distribution layer and a third temperature distribution layer from outside to inside, the first heat pipe is arranged in the first temperature distribution layer; the second heat pipe is arranged in the second temperature distribution layer; the third heat pipe is arranged in the third temperature distribution layer. The temperature of the first temperature distribution layer is ≤600K, the temperature of the second temperature distribution layer is 700K~800K, and the temperature of the third temperature distribution layer is 1200K~1300K.

[0018] The distribution positions of the first heat pipe, the second heat pipe and the third heat pipe in the insulation layer are determined by the temperature of the corresponding positions in the insulation layer. By adjusting the arrangement positions and angles of the heat pipes with different working temperatures, the cooling rate of the graphitization furnace is controlled to achieve uniformity of the internal thermal field of the graphitization furnace and improve the production efficiency of the graphitization furnace.

[0019] Preferably, the working medium of the first heat pipe is water, the working medium of the second heat pipe is mercury, and the working medium of the third heat pipe is sodium.

[0020] Preferably, along the thickness direction of the insulation layer, the vertical distance between the arrangement position of the first heat pipe in the insulation layer and the outermost side of the insulation layer is set to be a first distance, the vertical distance between the arrangement position of the second heat pipe in the insulation layer and the outermost side of the insulation layer is set to be a second distance, and the vertical distance between the arrangement position of the third heat pipe in the insulation layer and the outermost side of the insulation layer is set to be a third distance; the ratio of the first distance, the second distance and the third distance is 0.7~1:2~3:4.

[0021] In the present invention, the working temperatures of the plurality of heat pipes can be increased in sequence from the outside to the inside according to the vertical distance between the arrangement position of the heat pipe in the insulation layer and the outermost side of the insulation layer, so as to adjust the arrangement position of the heat pipes with different working temperatures on the insulation layer.

[0022] Preferably, the first distance is 70-100 mm; the second distance is 200-210 mm; and the third distance is 280-400 mm.

[0023] Preferably, a vertical line from the arrangement position of the third heat pipe in the insulation layer to the outermost side of the insulation layer is set as the baseline, and a vertical distance from the arrangement position of the second heat pipe in the insulation layer to the baseline is smaller than a vertical distance from the arrangement position of the first heat pipe in the insulation layer to the baseline.

[0024] In the present invention, on one side of the insulation layer, the third heat pipe is located between the second heat pipes, and the second heat pipe is located between the first heat pipes. Thus, according to the temperature distribution of the insulation layer, the high-temperature heat pipe corresponds to the high-temperature area of ​​the insulation layer, and the low-temperature heat pipe corresponds to the low-temperature area of ​​the insulation layer, so that the heat pipes with different working temperatures are matched with the temperature distribution in the corresponding insulation layer while achieving efficient cooling and shortening the cooling time, so as to avoid the problem of boiling of the medium in the heat pipe and ensure the stability of the heat transfer performance of the heat pipe.

[0025] Preferably, the number of the second heat pipes is greater than or equal to the number of the first heat pipes; and the number of the third heat pipes is greater than the number of the second heat pipes.

[0026] In the present invention, different numbers of heat pipes are arranged according to the temperature distribution of the insulation layer, wherein the first heat pipe is a low-temperature heat pipe, the second heat pipe is a medium-temperature heat pipe, and the third heat pipe is a high-temperature heat pipe. The high-temperature heat pipe is the main element for controlling the temperature distribution. By controlling the number of high-temperature heat pipes and matching the appropriate amount of medium-temperature heat pipes and low-temperature heat pipes, the cooling rate of the graphitization furnace can be controlled while achieving efficient cooling, achieving uniformity of the internal thermal field of the graphitization furnace, and improving the production efficiency of the graphitization furnace.

[0027] Preferably, the number of the first heat pipes is ≥2, and the number of the second heat pipes is ≥2.

[0028] Preferably, the number of the third heat pipes satisfies the following relationship:

[0029] ;in, is the number of the first heat pipes; is the number of the second heat pipes; is the number of the third heat pipes.

[0030] The present invention arranges different numbers of heat pipes to adapt to graphitization furnaces of different sizes, and adjusts the arrangement positions and angles of heat pipes of different working temperatures to control the cooling rate of the graphitization furnace, thereby achieving uniformity of the internal thermal field of the graphitization furnace and improving the production efficiency of the graphitization furnace.

[0031] Preferably, the graphitization furnace comprises a calcining material layer, and the calcining material layer is arranged in the thermal insulation layer; and the plurality of heat pipes are respectively arranged on both sides of the calcining material layer.

[0032] Preferably, one end of each of the heat pipes is obliquely inserted into the insulation layer, and the other end of each of the heat pipes is arranged on the upper side of the insulation layer and gradually moves away from the center of the graphitization furnace; the configuration angle of the heat pipe on the horizontal surface of the insulation layer is 15° to 60°.

[0033] In the present invention, the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are all inserted into the graphitization furnace at a certain inclination angle, so that the working fluid in the liquid wick can smoothly flow back from the condensation section to the evaporation section under the action of gravity, so as to enhance the startup performance and heat transfer performance of the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe.

[0034] Preferably, the heat pipe is arranged at an angle of 30° to 45° on the horizontal surface of the insulation layer. The heat pipe can be inserted into the graphitization furnace at an angle of 30° to 45° to the horizontal plane. This design not only optimizes the layout of the heat pipe, but also effectively enhances its heat transfer performance.

[0035] Preferably, the plurality of heat pipes are symmetrically arranged on the graphitization furnace. This design can further control the cooling rate of the graphitization furnace and achieve uniformity of the internal thermal field of the graphitization furnace.

[0036] Preferably, the cross-sectional shape of the heat pipe is circular, the inner diameter of the heat pipe is 89 mm, and the length of the heat pipe is 2 m.

[0037] Preferably, a plurality of heat pipes are arranged in parallel on one side of the insulation layer. The present invention arranges heat pipes on both sides of the graphitization furnace, and achieves the effect of rapidly cooling the graphitization furnace through the high heat exchange capacity of the heat pipes.

[0038] Preferably, the heat pipe has an evaporation section and a condensation section, the evaporation section is arranged in the insulation layer, and the condensation section is arranged in the cooling water device. The present invention facilitates heat exchange between the evaporation section of the heat pipe and the insulation layer by inserting the evaporation section of the heat pipe into the insulation layer. There is an insulation section between the evaporation section and the condensation section of the heat pipe, and the insulation section of the heat pipe is arranged in the refractory layer. In the present invention, heat is transferred from the graphite block to the insulation layer, and then absorbed by the evaporation section of the heat pipe. The internal working fluid of the heat pipe absorbs heat and evaporates, and becomes steam and is transferred to the condensation section of the heat pipe through the insulation section of the heat pipe. Under the action of the cooling water device, the steam condenses back into liquid, and flows back to the evaporation section of the heat pipe under the internal capillary force and gravity of the heat pipe, and the heat released by the phase change will be dissipated by the cooling water device. The cooling water device wraps the condensation section of the heat pipe, and the cooling water enters the device through the water inlet and is discharged from the water outlet. In this process, the cooling water effectively takes away the heat, thereby ensuring that the heat dissipation function of the heat pipe is maintained.

[0039] Preferably, the heat pipe is a tubular structure with closed ends, and the heat pipe includes a tube shell, a liquid wick and a steam zone from the outside to the inside, the liquid wick is arranged on the inner tube wall of the liquid wick; the steam zone is arranged in the liquid wick; the material of the tube shell is metal, and the liquid wick is composed of a capillary porous material.

[0040] Preferably, the heat pipe is in a negative pressure state and is filled with a liquid working medium.

[0041] Preferably, the material of the tube shell is any one of copper, nickel, stainless steel, tungsten or an alloy thereof; the material of the wick is the same as that of the tube shell; the material of the wick can be a metal powder sintered body, a metal wire mesh or a metal fiber material.

[0042] The second aspect of the present invention provides a graphitization furnace, comprising a baking material layer, a thermal insulation layer, a refractory layer and a heat pipe auxiliary cooling device; the heat pipe auxiliary cooling device is the heat pipe auxiliary cooling device described in the first aspect.

[0043] The third aspect of the present invention provides a heat pipe assisted cooling method for a graphitization furnace according to the second aspect, comprising the following steps:

[0044] The distribution positions and configuration angles of the first heat pipe, the second heat pipe, and the third heat pipe in the thermal insulation layer are adjusted to achieve uniformity of the internal thermal field of the graphitization furnace.

[0045] After the calcined material layer is heat treated, the cooling water device is started so that the first heat pipe, the second heat pipe and the third heat pipe respectively exchange heat with the cooling water device to achieve heat pipe auxiliary cooling of the graphitization furnace.

[0046] Preferably, the method for adjusting the distribution positions of the first heat pipe, the second heat pipe and the third heat pipe in the thermal insulation layer is:

[0047] Obtain the temperature intervals of different temperature distribution layers along the thickness direction in the thermal insulation layer; when the temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer detected is between 1200K and 1300K, arrange the third heat pipe in the temperature distribution layer corresponding to the temperature interval of 1200K to 1300K; when the temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer detected is between 700K and 800K, arrange the second heat pipe in the temperature distribution layer corresponding to the temperature interval of 700K to 800K; when the temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer detected is ≤600K, arrange the first heat pipe in the temperature distribution layer corresponding to the temperature interval of ≤600K.

[0048] In the present invention, the distribution positions of the first heat pipe, the second heat pipe and the third heat pipe in the insulation layer are determined by the temperature of the corresponding positions in the insulation layer. By adjusting the arrangement positions and angles of the heat pipes with different working temperatures, the cooling rate of the graphitization furnace is controlled, the uniformity of the internal thermal field of the graphitization furnace is achieved, and the production efficiency of the graphitization furnace is improved.

[0049] Preferably, the method for determining the corresponding position in the thermal insulation layer is to detect from the middle position of the thermal insulation layer to the position of 1200K to 1300K and then expand the detection to both sides.

[0050] Preferably, the first heat pipe, the second heat pipe and the third heat pipe are arranged at an angle of 15° to 60° on the horizontal surface of the thermal insulation layer.

[0051] In the present invention, the configuration angle of the first heat pipe, the second heat pipe and the third heat pipe in the thermal insulation layer only needs to be ensured to be an inclined angle, so as to ensure that the working medium in the liquid wick can flow back under gravity.

[0052] Beneficial effects of the present invention:

[0053] 1. The present invention modularizes the heat pipe cooling auxiliary device, designs the layout positions of heat pipes with different working temperatures, and cooperates with the cooling water device to achieve efficient cooling and shorten the cooling time, while solving the problem of insufficient heat dissipation efficiency of the current fan for high-temperature heat pipes and the problem that when the carbon-carbon composite material belts are connected into a heat pipe group, thermal stress concentration may be aggravated, thereby reducing the heat transfer performance of the heat pipe.

[0054] 2. The present invention arranges different numbers of heat pipes to adapt to graphitization furnaces of different sizes, and adjusts the arrangement positions and angles of heat pipes with different working temperatures to control the cooling rate of the graphitization furnace, thereby achieving uniformity of the internal thermal field of the graphitization furnace and improving the production efficiency of the graphitization furnace, so as to be effectively applied in the artificial graphite preparation industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Schematic diagram of the structure of the graphitization furnace.

[0056] Figure 2 A front schematic diagram of a heat pipe cooling auxiliary device provided in one embodiment of the present invention.

[0057] Figure 3 A side schematic diagram of a heat pipe cooling auxiliary device provided in one embodiment of the present invention.

[0058] Figure 4 A schematic diagram of various parts of a heat pipe inserted into a graphitization furnace according to an embodiment of the present invention.

[0059] Figure 5 Schematic diagram of the connection portion between the heat pipe and the cooling water device in one embodiment of the present invention.

[0060] Figure 6 FIG. 1 is a diagram showing the working principle of a heat pipe in one embodiment of the present invention.

[0061] Figure 7 The graphite furnaces with high temperature heat pipes, medium temperature heat pipes, low temperature heat pipes and a single high temperature heat pipe are compared with the maximum temperature over time.

[0062] Figure 8 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace in Example 1 that is cooled jointly by the high-temperature heat pipe, the medium-temperature heat pipe, and the low-temperature heat pipe.

[0063] Fig. 9 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace in Example 2 that is cooled jointly by the high-temperature heat pipe, the medium-temperature heat pipe and the low-temperature heat pipe.

[0064] Fig.10 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace of Comparative Example 1 which only uses high-temperature heat pipe cooling.

[0065] Fig.11 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace of Comparative Example 2 which only uses high-temperature heat pipe cooling.

[0066] Fig.12 This is a local temperature cloud diagram of the horizontal surface of a graphitization furnace without a heat pipe.

[0067] Description of reference numerals:

[0068] 1. roasting material layer; 2. thermal insulation layer; 3. refractory layer; 4. heat pipe; 41. first heat pipe; 42. second heat pipe; 43. third heat pipe; 44. evaporation section; 45. insulation section; 46. condensation section; 47. tube shell; 48. liquid absorption core; 49. steam area; 5. cooling water device; 51. water inlet; 52. water outlet. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0070] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0071] Traditional graphitization furnaces generally use natural cooling to cool down. Although this method is simple and easy to implement, it takes a long time and occupies more than 90% of the production cycle, which seriously restricts the improvement of production efficiency. In order to overcome this problem, the industry has begun to explore more efficient cooling technologies.

[0072] Early cooling module designs, such as waste heat pipe coils, metal straight pipes or serpentine coils, were tried in the cooling system of graphitization furnaces. However, these cooling methods exposed the problem of low cooling efficiency and failure to meet the demand for rapid cooling in actual applications. Especially in high temperature environments above 2700K, the heat dissipation effect of these traditional cooling modules is greatly reduced and cannot meet the production needs of graphitization furnaces.

[0073] In order to further improve the cooling efficiency of graphitization furnaces, heat pipe cooling technology has gradually come into people's view. Heat pipe cooling mainly achieves efficient heat exchange by absorbing or releasing heat when the cooling medium changes its physical state. However, in the actual application of graphitization furnaces, heat pipe cooling technology also faces many challenges.

[0074] For example, prior art 1 with publication number CN116608698A proposes a heat pipe cooling graphitization furnace, in which a fan is mainly used to cool the high-temperature heat pipe. However, the heat dissipation effect of the fan on the high-temperature heat pipe is limited and cannot meet the heat dissipation requirements of high-temperature heat pipes above 2700K.

[0075] In addition, the prior art 2 with the publication number CN219914097U proposes a large temperature difference combined heat pipe for cooling the graphitization furnace. This technical solution is connected into a heat pipe group through a carbon-carbon composite material belt to achieve rapid cooling of the graphitization furnace. However, since the heat pipe will be deeply buried in the graphitization furnace, the application of the carbon-carbon composite material belt will inevitably cause physical damage to the internal structure of the graphitization furnace, thereby affecting the thermal stability of the furnace body. In addition, this technical solution also needs to deal with a key problem in practical applications. The extreme and changeable temperature environment inside the graphitization furnace, especially when the temperature gradient increases sharply, is prone to cause thermal stress concentration. In the long run, it will affect the overall service life of the furnace body, especially after the temperature rises sharply, which often causes the working medium of the high-temperature heat pipe, such as sodium, potassium, etc., to boil, reducing the heat transfer performance of the heat pipe.

[0076] Based on this, the present invention proposes a heat pipe auxiliary cooling device for a graphitization furnace, a graphitization furnace and a method. The present invention modularizes the heat pipe cooling auxiliary device, designs the layout positions of heat pipes with different working temperatures, and cooperates with a cooling water device to achieve efficient cooling and shorten the cooling time, while solving the problem of insufficient heat dissipation efficiency of the current fan for high-temperature heat pipes and the problem that when carbon-carbon composite material strips are connected into a heat pipe group, thermal stress concentration may be aggravated, reducing the heat transfer performance of the heat pipe.

[0077] The technical solution of the present invention is further described below through specific embodiments.

[0078] Unless otherwise specified, the methods described in the following examples are all conventional methods; the reagents, materials and equipment described are all commercially available unless otherwise specified.

[0079] See also Figure 1 , the graphitization furnace includes a baking material layer 1, a thermal insulation layer 2 and a refractory layer 3. Among them, the baking material layer 1 is a graphite block, and the graphite block is placed in the middle of the thermal insulation layer 2. The refractory layer 3 is made of refractory bricks, and the refractory bricks cover the sides and bottom of the thermal insulation layer 2. The thermal insulation layer 2 is formed by thermal insulation material. By connecting voltage to the thermal insulation layer 2, it is used as a heating resistor, and the graphite block is heated by the heat generated by the resistor, thereby completing the production of artificial graphite. Specifically, when the graphite block is at a high temperature of more than 2700K, the carbon with an amorphous chaotic layer structure can be transformed into three-dimensional ordered artificial graphite crystals. When the graphite block reaches a high temperature of 3000K, the thermal insulation layer 2 stops energizing.

[0080] In order to improve the cooling efficiency of the graphitization furnace and meet the demand for rapid cooling, the embodiment of the present invention adopts a heat pipe auxiliary cooling device applied to the graphitization furnace, which is configured to quickly cool the graphitization furnace after heat treatment, solve the problem of insufficient heat dissipation efficiency of the fan for the high-temperature heat pipe, and the problem that when the carbon-carbon composite material belts are connected into a heat pipe group, thermal stress concentration may be aggravated, thereby reducing the heat transfer performance of the heat pipe.

[0081] See also Figure 2 and Figure 3 The heat pipe auxiliary cooling device of the graphitization furnace is applied to the graphitization furnace, and the graphitization furnace has a heat preservation layer 2. The heat pipe auxiliary cooling device includes: a heat absorption unit and an auxiliary cooling unit. Among them, the heat absorption unit is mainly used to absorb heat from the graphitization furnace. The heat absorption unit includes a plurality of heat pipes 4, and is arranged on the heat preservation layer 2 in sequence from the outside to the inside; the plurality of heat pipes 4 are divided into a plurality of heat pipe groups, and the working temperature of the plurality of heat pipe groups increases in sequence from the outside to the inside.

[0082] Preferably, the insulation layer 2 forms a plurality of temperature distribution layers from outside to inside; a plurality of heat pipes 4 are sequentially arranged on the corresponding temperature distribution layers from outside to inside; the working temperatures of the heat pipes 4 on the same temperature distribution layer are the same. The embodiment of the present invention arranges different numbers of heat pipes to accommodate graphitization furnaces of different sizes, and adjusts the arrangement positions and angles of heat pipes with different working temperatures to control the cooling rate of the graphitization furnace, thereby achieving uniformity of the internal thermal field of the graphitization furnace and improving the production efficiency of the graphitization furnace.

[0083] like Figure 5The auxiliary cooling unit includes a cooling water device 5, and one end of the heat absorption unit is connected to the cooling water device 5. The cooling water device is used to realize heat exchange of multiple heat pipes 4 to improve the heat exchange efficiency. The embodiment of the present invention modularizes the heat pipe cooling auxiliary device, designs the layout positions of heat pipes with different working temperatures, and cooperates with the cooling water device to achieve efficient cooling, shorten the cooling time, and solve the problem of thermal stress concentration.

[0084] like Figure 5 , the evaporation section of the heat pipe is inserted into the insulation layer to exchange heat with it. The insulation section of the heat pipe is arranged inside the refractory layer, and the condensation section of the heat pipe is connected to the cooling water device. The heat is transferred from the graphite block to the insulation layer, and then absorbed by the evaporation section of the heat pipe. The internal working fluid of the heat pipe absorbs the heat and evaporates, turning into steam and transferring it to the condensation section of the heat pipe through the insulation section of the heat pipe. Under the action of the cooling water device, the steam condenses back into liquid, and flows back to the evaporation section of the heat pipe under the action of the internal capillary force and gravity of the heat pipe, while the heat released by the phase change will be dissipated by the cooling water device. The cooling water device wraps the condensation section of the heat pipe, and the cooling water enters the device through the water inlet 51 and is discharged from the water outlet 52. In this process, the cooling water effectively takes away the heat, thereby ensuring that the heat dissipation function of the heat pipe is maintained.

[0085] On the basis of the above-mentioned embodiment, as a more preferred embodiment, Figure 2 and Figure 3 , the multiple heat pipe groups are respectively recorded as a first heat pipe group, a second heat pipe group and a third heat pipe group, the heat pipes of the first heat pipe group are recorded as first heat pipes 41, the heat pipes of the second heat pipe group are recorded as second heat pipes 42, and the heat pipes of the third heat pipe group are recorded as third heat pipes 43, and the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 are arranged on the insulation layer 2 in sequence from the outside to the inside; the operating temperatures of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 increase in sequence.

[0086] In an embodiment of the present invention, the first heat pipe is a low-temperature heat pipe, the second heat pipe is a medium-temperature heat pipe, and the third heat pipe is a high-temperature heat pipe. Among them, the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are located on the side of the insulation layer 2, at a certain distance from the inner side of the refractory layer. When the graphite block reaches a high temperature of 3000K, the insulation layer 2 stops being powered, and the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe exchange heat with the insulation layer 2. Heat is transferred from the insulation layer 2 to the evaporation section of the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe, and then to the condensation section of the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe, and finally connected to the cooling water device through the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe, respectively, to transfer heat to the external environment.

[0087] On the basis of the above embodiment, as a more preferred embodiment, the working temperature of the first heat pipe 41 is 300K~550K; the first heat pipe 41 is arranged in the temperature distribution layer with a temperature of ≤600K in the insulation layer 2; the working temperature of the second heat pipe 42 is 550K~750K; the second heat pipe 42 is arranged in the temperature distribution layer with a temperature of 700K~800K in the insulation layer 2; the working temperature of the third heat pipe 43 is 750K~1200K; the third heat pipe 43 is arranged in the temperature distribution layer with a temperature of 1200K~1300K in the insulation layer 2.

[0088] Preferably, the working medium of the first heat pipe 41 is water, the working medium of the second heat pipe 42 is mercury, and the working medium of the third heat pipe 43 is sodium. For example, the low-temperature heat pipe is 2000 mm long, 89 mm in diameter, and has an operating temperature of 300K to 550K. The working medium in the wick is water, and it is inserted from the side at an angle of 30 degrees to the horizontal ground to 80 mm from the inside of the refractory layer 3. The medium-temperature heat pipe is 2000 mm long, 89 mm in diameter, and has an operating temperature of 550K to 750K. The working medium in the wick is mercury, and it is inserted from the side at an angle of 30 degrees to the horizontal ground to 200 mm from the inside of the refractory layer 3. The high-temperature heat pipe is 2000 mm long, 89 mm in diameter, and has an operating temperature of 750K to 1200K. The working medium in the wick is sodium, and it is inserted from the side at an angle of 30 degrees to the horizontal ground to 320 mm from the inside of the refractory layer 3.

[0089] In the embodiment of the present invention, the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are all inserted into the graphitization furnace at a certain inclination angle, so that the working fluid in the liquid absorption core can smoothly flow back from the condensation section to the evaporation section under the action of gravity, so as to enhance the startup performance and heat transfer performance of the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe.

[0090] On the basis of the above embodiment, as a more preferred embodiment, along the thickness direction of the thermal insulation layer (2), the vertical distance between the arrangement position of the first heat pipe 41 in the thermal insulation layer 2 and the outermost side of the thermal insulation layer 2 is set as the first distance, the vertical distance between the arrangement position of the second heat pipe in the thermal insulation layer 2 and the outermost side of the thermal insulation layer 2 is set as the second distance, and the vertical distance between the arrangement position of the third heat pipe 43 in the thermal insulation layer 2 and the outermost side of the thermal insulation layer 2 is set as the third distance; the ratio of the first distance, the second distance and the third distance is 0.7~1:2~3:4. For example, the first distance is 70~100mm, preferably 80mm; the second distance is 200~210mm, preferably 200mm; the third distance is 280~400mm, preferably 320mm.

[0091] Preferably, the vertical line from the arrangement position of the third heat pipe 43 in the insulation layer 2 to the outermost side of the insulation layer 2 is set as the baseline, and the vertical distance from the arrangement position of the second heat pipe 42 in the insulation layer 2 to the baseline is smaller than the vertical distance from the arrangement position of the first heat pipe 41 in the insulation layer 2 to the baseline.

[0092] Based on the above embodiment, as a more preferred embodiment, the number of the second heat pipes 42 is greater than or equal to the number of the first heat pipes 41; the number of the third heat pipes 43 is greater than the number of the second heat pipes 42. Preferably, the number of the first heat pipes 41 is ≥ 2, and the number of the second heat pipes 42 is ≥ 2. Preferably, the number of the third heat pipes 43 satisfies the following relationship: ;in, is the number of the first heat pipes 41; is the number of the second heat pipes 42; is the number of the third heat pipes 43. The embodiment of the present invention arranges different numbers of heat pipes to adapt to graphitization furnaces of different sizes, and adjusts the arrangement positions and angles of heat pipes of different working temperatures to control the cooling rate of the graphitization furnace, thereby achieving uniformity of the internal thermal field of the graphitization furnace and improving the production efficiency of the graphitization furnace.

[0093] On the basis of the above embodiment, as a more preferred embodiment, the graphitization furnace includes a calcining material layer 1, and the calcining material layer 1 is arranged in the thermal insulation layer 2; a plurality of heat pipes 4 are respectively arranged on both sides of the calcining material layer 1.

[0094] Preferably, one end of each heat pipe 4 is obliquely inserted into the insulation layer 2, and the other end of each heat pipe 4 is arranged on the upper side of the insulation layer 2 and gradually away from the center of the graphitization furnace; the configuration angle of the heat pipe 4 on the horizontal surface of the insulation layer 2 is 15 to 60 degrees. Preferably, the configuration angle of the heat pipe 4 on the horizontal surface of the insulation layer 2 is 30 to 45 degrees. Preferably, multiple heat pipes 4 are symmetrically arranged on the graphitization furnace.

[0095] In some embodiments of the present invention, the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are obliquely inserted into the graphitization furnace at a certain angle to the horizontal ground. With this arrangement, the working fluid condensed inside the heat pipe is not only returned to the evaporation section under the action of the capillary force of the liquid wick, but also assisted by the gravity. This design significantly enhances the startup performance and heat transfer efficiency of the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe.

[0096] Based on the above embodiment, as a more preferred embodiment, the cross-sectional shape of the heat pipe 4 is circular, the inner diameter of the heat pipe 4 is 89 mm, and the length of the heat pipe 4 is 2 m. Figure 2, low-temperature heat pipes, medium-temperature heat pipes and high-temperature heat pipes are inserted into the graphitization furnace in parallel. 2 low-temperature heat pipes, 4 medium-temperature heat pipes and 5 high-temperature heat pipes are combined in parallel, with a top-bottom spacing of 180mm to form a row. The interval between each row of heat pipes is 1m. Figure 2 The plug hole is designed to be elliptical, which is mainly because the heat pipe is inserted into the periphery of the graphitization furnace at an angle of 30°, leaving a mark on the peripheral wall of the graphitization furnace. In the embodiment of the present invention, the heat pipe can be inserted into the graphitization furnace at an angle of 30° to the horizontal plane. This design not only optimizes the layout of the heat pipe, but also effectively enhances its heat transfer performance.

[0097] Based on the above embodiment, as a more preferred embodiment, a plurality of heat pipes are arranged in parallel on one side of the insulation layer. By arranging heat pipes on both sides of the graphitization furnace, the high heat exchange capacity of the heat pipes can achieve the effect of rapidly cooling the graphitization furnace.

[0098] On the basis of the above-mentioned embodiment, as a more preferred embodiment, Figure 4 , the heat pipe 4 has an evaporation section 44 and a condensation section 46, the evaporation section 44 is arranged in the insulation layer 2, and the condensation section 46 is arranged in the cooling water device 5. In the embodiment of the present invention, by inserting the evaporation section of the heat pipe into the insulation layer, it is helpful to exchange heat between the evaporation section of the heat pipe and the insulation layer. There is an insulating section between the evaporation section and the condensation section of the heat pipe, and the insulating section of the heat pipe is arranged in the refractory layer. In the embodiment of the present invention, heat is transferred from the graphite block to the insulation layer, and then absorbed by the evaporation section of the heat pipe. The internal working fluid of the heat pipe absorbs heat and evaporates, and becomes steam and is transferred to the condensation section of the heat pipe through the insulating section of the heat pipe. Under the action of the cooling water device, the steam condenses back into liquid, and flows back to the evaporation section of the heat pipe under the internal capillary force and gravity of the heat pipe, and the heat released by the phase change will be dissipated by the cooling water device. The cooling water device wraps the condensation section of the heat pipe, and the cooling water enters the device through the water inlet and is discharged from the water outlet. In this process, the cooling water effectively takes away the heat, thereby ensuring that the heat dissipation function of the heat pipe is maintained.

[0099] On the basis of the above-mentioned embodiment, as a more preferred embodiment, Figure 6 The heat pipe 4 is a tubular structure with closed ends. The heat pipe 4 includes a tube shell 47, a liquid wick 48 and a steam zone 49 from the outside to the inside. The liquid wick 48 is arranged on the inner tube wall of the liquid wick 48; the steam zone 49 is arranged in the liquid wick 48; the material of the tube shell 47 is metal, and the liquid wick 48 is composed of a capillary porous material. Preferably, the heat pipe is in a negative pressure state and is filled with a liquid working medium. Preferably, the material of the tube shell is any one of copper, nickel, stainless steel, tungsten or an alloy thereof; the material of the liquid wick is the same as that of the tube shell; the material of the liquid wick can be a metal powder sintered body, a metal wire mesh or a metal fiber material.

[0100] On the basis of the above-mentioned embodiment, as a more preferred embodiment, the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are tubular metal structures with closed ends, which are respectively a tube shell, a liquid wick and a steam zone from the outside to the inside. A certain working fluid is encapsulated in the liquid wick. The low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are divided into three parts: an evaporation section, an adiabatic section and a condensation section. When the low-temperature heat pipe, the medium-temperature heat pipe and the high-temperature heat pipe are working, the external heat source supplies heat to the evaporation section, so that the heat flow enters from the outer wall of the evaporation section, the working fluid evaporates, and the steam is pushed by the pressure difference through the adiabatic section to the condensation section. In the condensation section, the steam condenses as the temperature decreases, releasing the latent heat of vaporization, and the condensed working fluid will return to the evaporation section under the action of the capillary force of the liquid wick, thereby completing a cycle. Under continuous circulation, heat is continuously transferred from the evaporation section to the condensation section, and the working fluid evaporates, the steam flows and condenses, and the condensate refluxes inside.

[0101] Based on the above embodiments, an embodiment of the present invention provides a heat pipe assisted cooling method for a graphitization furnace, comprising the following steps:

[0102] S1. Adjust the distribution positions and configuration angles of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 in the thermal insulation layer 2 to achieve uniformity of the internal thermal field of the graphitization furnace.

[0103] S1.1. The method for adjusting the distribution positions of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 in the thermal insulation layer 2 is:

[0104] The temperature intervals of different temperature distribution layers in the thermal insulation layer 2 along the thickness direction are obtained.

[0105] When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer 2 is between 1200K and 1300K, the third heat pipe 43 is arranged in the temperature distribution layer corresponding to the temperature interval of 1200K to 1300K.

[0106] When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer 2 is between 700K and 800K, the second heat pipe 42 is arranged in the temperature distribution layer corresponding to the temperature interval of 700K to 800K.

[0107] When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer 2 is ≤600K, the first heat pipe 41 is arranged in the temperature distribution layer corresponding to the temperature interval of ≤600K.

[0108] In the embodiment of the present invention, the distribution positions of the first heat pipe, the second heat pipe and the third heat pipe in the insulation layer are determined by the temperature of the corresponding positions in the insulation layer. By adjusting the arrangement positions and angles of the heat pipes with different working temperatures, the cooling rate of the graphitization furnace is controlled, the uniformity of the internal thermal field of the graphitization furnace is achieved, and the production efficiency of the graphitization furnace is improved.

[0109] S1.2. Adjust the configuration angle of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 in the thermal insulation layer 2 to 15° to 60°.

[0110] S1.3. According to step S1.1 and step S1.2, the distribution positions and configuration angles of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 in the thermal insulation layer 2 are adjusted to achieve uniformity of the internal thermal field of the graphitization furnace.

[0111] S2. After the calcined material layer 1 is heat treated, the cooling water device 5 is started so that the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 respectively exchange heat with the cooling water device 5 to achieve heat pipe auxiliary cooling of the graphitization furnace.

[0112] The heat pipe assisted cooling method for the graphitization furnace is further described below through specific embodiments.

[0113] Example 1

[0114] A heat pipe assisted cooling method for a graphitization furnace comprises the following steps:

[0115] Step 1, the method for adjusting the distribution positions of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 in the thermal insulation layer 2 is:

[0116] The temperature intervals of different temperature distribution layers in the thermal insulation layer 2 along the thickness direction are obtained.

[0117] When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer 2 is between 1200K and 1300K, the third heat pipe 43 is arranged in the temperature distribution layer corresponding to the temperature interval of 1200K to 1300K.

[0118] When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer 2 is between 700K and 800K, the second heat pipe 42 is arranged in the temperature distribution layer corresponding to the temperature interval of 700K to 800K.

[0119] When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer 2 is ≤600K, the first heat pipe 41 is arranged in the temperature distribution layer corresponding to the temperature interval of ≤600K.

[0120] Step 2, adjusting the configuration angle of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 in the thermal insulation layer 2 to 30°.

[0121] Step 3, according to step 1 and step 2, adjusting the distribution position and configuration angle of the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 in the insulation layer 2 to achieve uniformity of the internal thermal field of the graphitization furnace.

[0122] Step 4, after the calcined material layer 1 is heat treated, the cooling water device 5 is started so that the first heat pipe 41, the second heat pipe 42 and the third heat pipe 43 respectively exchange heat with the cooling water device 5 to achieve heat pipe auxiliary cooling of the graphitization furnace.

[0123] In Example 1, the first heat pipe 41 is a low-temperature heat pipe, with two of them; the second heat pipe 42 is a medium-temperature heat pipe, with six of them; the third heat pipe 43 is a high-temperature heat pipe, with four of them, as shown in FIG. Figure 8 .

[0124] Example 2

[0125] A heat pipe assisted cooling method for a graphitization furnace is basically the same as the method of Example 1, except that in Example 2, the first heat pipe 41 is a low-temperature heat pipe, which has two; the second heat pipe 42 is a medium-temperature heat pipe, which has two; and the third heat pipe 43 is a high-temperature heat pipe, which has two. Fig. 9 .

[0126] Comparative Example 1

[0127] A heat pipe assisted cooling method for a graphitization furnace, which differs from Embodiment 1 in that only a third heat pipe 43 is provided. The specific method comprises the following steps:

[0128] Step 1, the method for adjusting the distribution position of the third heat pipe 43 in the thermal insulation layer 2 is:

[0129] The temperature intervals of different temperature distribution layers in the thermal insulation layer 2 along the thickness direction are obtained.

[0130] When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer 2 is between 1200K and 1300K, the third heat pipe 43 is arranged in the temperature distribution layer corresponding to the temperature interval of 1200K to 1300K.

[0131] Step 2, adjusting the configuration angle of the third heat pipe 43 in the thermal insulation layer 2 to 30°.

[0132] Step 3, according to step 1 and step 2, the distribution position and configuration angle of the third heat pipe 43 in the thermal insulation layer 2 are adjusted to adjust the uniformity of the internal thermal field of the graphitization furnace.

[0133] Step 4, after the calcined material layer 1 is heat treated, the cooling water device 5 is started so that the third heat pipes 43 respectively exchange heat with the cooling water device 5 to achieve heat pipe auxiliary cooling of the graphitization furnace.

[0134] In comparative example 1, the third heat pipe 43 is a high temperature heat pipe and has 6 pieces, such as Fig.10 .

[0135] Comparative Example 2

[0136] A heat pipe assisted cooling method for a graphitization furnace is basically the same as the method in comparative example 1, except that in comparative example 2, the third heat pipe 43 is a high-temperature heat pipe having two, such as Fig.11 .

[0137] The distribution position and configuration angle of the third heat pipes 43 in Example 1 and Example 2 are the same as the distribution position and configuration angle of the third heat pipes 43 in Comparative Example 1 and Comparative Example 2.

[0138] like Figure 7 , the graphitization furnace of Example 2, which is cooled by high-temperature heat pipes, medium-temperature heat pipes and low-temperature heat pipes, is taken as Scheme A. The graphitization furnace of Comparative Example 1, which is cooled by only high-temperature heat pipes, is taken as Scheme B. Schemes A and B are simulated and compared. The comparison results of the maximum temperature change curves of the graphitization furnace of Example 2 and the graphitization furnace of Comparative Example 1 are as follows: Figure 7 .

[0139] Figure 7 The results show that after cooling for 250 hours, the maximum temperature of the graphitization furnace dropped from 3100K to about 850K. At this time, since the working temperature of the high-temperature heat pipe dropped to 750K, the heat dissipation capacity was lost. Therefore, in Scheme A, the medium-temperature heat pipe and the low-temperature heat pipe continue to work, while in Scheme B, only natural air convection cooling is used. After cooling for 600 hours, the maximum temperature of the graphitization furnace in Scheme A dropped to about 624K, while the maximum temperature of the graphitization furnace in Scheme B was about 820K. At this time, the working temperature of the medium-temperature heat pipe in Scheme A dropped to 550K, losing the heat dissipation capacity, leaving only the low-temperature heat pipe to continue working. After the final cooling for 1000 hours, the maximum temperature of the graphitization furnace in Scheme A dropped to about 559K, while the maximum temperature of the graphitization furnace in Scheme B was about 790K. This proves that the cooling efficiency of the graphitization furnace is higher when high-temperature heat pipes, medium-temperature heat pipes and low-temperature heat pipes are used to cool the graphitization furnace at the same time, which also proves the superiority of Scheme A corresponding to Example 2 of the present invention.

[0140] Figure 8 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace in Example 1 that is cooled jointly by the high-temperature heat pipe, the medium-temperature heat pipe, and the low-temperature heat pipe. Fig. 9 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace of Comparative Example 1 which only uses high-temperature heat pipe cooling. Fig.10 This is a local temperature cloud diagram of the horizontal surface of a graphitization furnace without a heat pipe.

[0141] Fig. 9 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace in Example 2 that is cooled jointly by the high-temperature heat pipe, the medium-temperature heat pipe and the low-temperature heat pipe.

[0142] Fig.10 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace of Comparative Example 1 which only uses high-temperature heat pipe cooling.

[0143] Fig.11 This is a local temperature cloud diagram of the horizontal surface of the graphitization furnace of Comparative Example 2 which only uses high-temperature heat pipe cooling.

[0144] Fig.12 This is a local temperature cloud diagram of the horizontal surface of a graphitization furnace without a heat pipe.

[0145] like Fig.12 ,In the case of no heat pipe, the horizontal surface of the graphitization furnace shows a sharply increased temperature distribution, inducing the phenomenon of thermal stress concentration.

[0146] like Fig.10 and Fig.11 ,Compared with the graphitization furnace without heat pipes, the horizontal surfaces of the graphitization furnaces in Comparative Examples 1 and 2, which are cooled only by high-temperature heat pipes, show uneven temperature cooling, with local low temperatures and local excessively high temperatures.

[0147] like Figure 8 and Fig. 9 Compared with the graphitization furnaces in Comparative Examples 1 and 2 that are cooled only by high-temperature heat pipes, the working surface temperature of the graphitization furnaces in Examples 1 and 2 that are cooled by high-temperature heat pipes, medium-temperature heat pipes, and low-temperature heat pipes is relatively more uniform, which shows that by designing the arrangement positions of heat pipes with different working temperatures, the temperature field of the insulation layer can be optimized to make the temperature distribution uniform, and there is no thermal stress concentration phenomenon caused by a sharp increase in temperature gradient. Moreover, the working temperatures of multiple heat pipes are increased in sequence from the outside to the inside, so that the heat pipes with different working temperatures match the temperature distribution in the corresponding insulation layer, avoiding exceeding the working limit of the heat pipe after a sharp increase in temperature. In addition, by using a heat absorption unit in conjunction with a cooling water device, Examples 1 and 2 can avoid the problem of boiling of the medium in the heat pipe while achieving efficient cooling and shortening the cooling time, so as to ensure the stability of the heat transfer performance of the heat pipe.

[0148] In summary, the embodiments of the present invention can achieve efficient cooling by modularly designing the heat pipe cooling auxiliary device, designing the layout positions of heat pipes with different working temperatures, and cooperating with a cooling water device, thereby greatly accelerating the cooling process of the graphitization furnace and the production efficiency of artificial graphite, and can be effectively applied in the artificial graphite preparation industry.

[0149] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A heat pipe auxiliary cooling device for a graphitization furnace, applied to a graphitization furnace, wherein the graphitization furnace has a heat insulation layer (2), characterized in that: The heat pipe auxiliary cooling device comprises: The heat absorbing unit comprises a plurality of heat pipes (4) which are sequentially arranged on the heat-insulating layer (2) from the outside to the inside; the heat-insulating layer (2) forms a plurality of temperature distribution layers from the outside to the inside; the plurality of heat pipes (4) are sequentially arranged on the temperature distribution layers corresponding thereto from the outside to the inside; the plurality of heat pipes (4) are divided into a plurality of heat pipe groups, the working temperatures of the plurality of heat pipe groups sequentially increase from the outside to the inside, and are configured so that heat pipes with different working temperatures match the temperature distribution in the corresponding heat-insulating layer, thereby achieving uniformity of the internal thermal field of the graphitization furnace; The auxiliary cooling unit comprises a cooling water device (5), and one end of the heat absorption unit is connected to the cooling water device (5).

2. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 1, characterized in that: The operating temperatures of the heat pipes (4) located on the same temperature distribution layer are all the same.

3. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 2, characterized in that: The plurality of heat pipe groups are respectively recorded as a first heat pipe group, a second heat pipe group and a third heat pipe group; the heat pipes of the first heat pipe group are recorded as first heat pipes (41), the heat pipes of the second heat pipe group are recorded as second heat pipes (42), and the heat pipes of the third heat pipe group are recorded as third heat pipes (43); and the first heat pipes (41), the second heat pipes (42) and the third heat pipes (43) are arranged in sequence on the thermal insulation layer (2) from the outside to the inside; The operating temperatures of the first heat pipe (41), the second heat pipe (42) and the third heat pipe (43) increase sequentially.

4. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 3, characterized in that: The working temperature of the first heat pipe (41) is 300K to 550K, and the first heat pipe (41) is arranged in a temperature distribution layer in the thermal insulation layer (2) with a temperature of ≤600K; The operating temperature of the second heat pipe (42) is 550K to 750K, and the second heat pipe (42) is arranged in a temperature distribution layer in the thermal insulation layer (2) with a temperature of 700K to 800K; The working temperature of the third heat pipe (43) is 750K-1200K, and the third heat pipe (43) is arranged in a temperature distribution layer in the thermal insulation layer (2) with a temperature of 1200K-1300K.

5. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 3, characterized in that: The working medium of the first heat pipe (41) is water, the working medium of the second heat pipe (42) is mercury, and the working medium of the third heat pipe (43) is sodium.

6. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 3, characterized in that: Along the thickness direction of the thermal insulation layer (2), the vertical distance between the arrangement position of the first heat pipe (41) in the thermal insulation layer (2) and the outermost side of the thermal insulation layer (2) is set as a first distance, the vertical distance between the arrangement position of the second heat pipe (42) in the thermal insulation layer (2) and the outermost side of the thermal insulation layer (2) is set as a second distance, and the vertical distance between the arrangement position of the third heat pipe (43) in the thermal insulation layer (2) and the outermost side of the thermal insulation layer (2) is set as a third distance; The ratio of the first distance, the second distance and the third distance is 0.7-1:2-3:

4.

7. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 3, characterized in that: A vertical line from the arrangement position of the third heat pipe (43) in the thermal insulation layer (2) to the outermost side of the thermal insulation layer (2) is set as a baseline, and a vertical distance from the arrangement position of the second heat pipe (42) in the thermal insulation layer (2) to the baseline is smaller than a vertical distance from the arrangement position of the first heat pipe (41) in the thermal insulation layer (2) to the baseline.

8. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 3, characterized in that: The number of the second heat pipes (42) is greater than or equal to the number of the first heat pipes (41); The number of the third heat pipes (43) is greater than the number of the second heat pipes (42).

9. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 8, characterized in that: The number of the first heat pipes (41) is ≥2, and the number of the second heat pipes (42) is ≥2.

10. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 9, characterized in that: The number of the third heat pipes (43) satisfies the following relationship: Wherein, n1 is the number of the first heat pipes (41); n2 is the number of the second heat pipes (42); and n3 is the number of the third heat pipes (43).

11. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 1, characterized in that: The graphitization furnace comprises a calcining material layer (1), wherein the calcining material layer (1) is arranged in the thermal insulation layer (2); and a plurality of heat pipes (4) are respectively arranged on both sides of the calcining material layer (1).

12. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 11, characterized in that: One end of each of the heat pipes (4) is obliquely inserted into the thermal insulation layer (2), and the other end of each of the heat pipes (4) is arranged on the upper side of the thermal insulation layer (2) and gradually moves away from the center of the graphitization furnace; The heat pipe (4) is arranged at an angle of 15° to 60° on the horizontal surface of the thermal insulation layer (2).

13. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 11, characterized in that: The plurality of heat pipes (4) are symmetrically arranged on the graphitization furnace.

14. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 1, characterized in that: The cross-sectional shape of the heat pipe (4) is circular, the inner diameter of the heat pipe (4) is 89 mm, and the length of the heat pipe (4) is 2 m.

15. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 1, characterized in that: The heat pipe (4) comprises an evaporation section (44) and a condensation section (46); the evaporation section (44) is arranged in the thermal insulation layer (2), and the condensation section (46) is arranged in the cooling water device (5).

16. The heat pipe auxiliary cooling device for a graphitization furnace according to claim 1, characterized in that: The heat pipe (4) is a tubular structure with two ends closed. The heat pipe (4) comprises, from the outside to the inside, a tube shell (47), a liquid wick (48) and a steam zone (49). The liquid wick (48) is arranged on the inner tube wall of the liquid wick (48); the steam zone (49) is arranged inside the liquid wick (48); The material of the tube shell (47) is metal, and the liquid absorption core (48) is made of capillary porous material.

17. A graphitization furnace, comprising a calcining material layer (1), a heat-insulating layer (2), a refractory layer (3) and a heat pipe auxiliary cooling device; characterized in that: The heat pipe auxiliary cooling device is the heat pipe auxiliary cooling device according to claim 3.

18. A heat pipe assisted cooling method for a graphitization furnace according to claim 17, characterized in that: The following steps are involved: Adjusting the distribution positions and configuration angles of the first heat pipe (41), the second heat pipe (42), and the third heat pipe (43) in the thermal insulation layer (2) to achieve uniformity of the internal thermal field of the graphitization furnace; After the calcined material layer (1) is heat treated, the cooling water device (5) is started so that the first heat pipe (41), the second heat pipe (42) and the third heat pipe (43) respectively exchange heat with the cooling water device (5) to achieve heat pipe auxiliary cooling of the graphitization furnace.

19. The heat pipe assisted cooling method for a graphitization furnace according to claim 18, characterized in that: The method for adjusting the distribution positions of the first heat pipe (41), the second heat pipe (42) and the third heat pipe (43) in the thermal insulation layer (2) is: Obtaining the temperature intervals of different temperature distribution layers along the thickness direction in the thermal insulation layer (2); When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer (2) is between 1200K and 1300K, a third heat pipe (43) is arranged in the temperature distribution layer corresponding to the temperature interval of 1200K to 1300K; When the detected temperature range of the temperature distribution layer along the thickness direction in the thermal insulation layer (2) is between 700K and 800K, a second heat pipe (42) is arranged in the temperature distribution layer corresponding to the temperature range of 700K to 800K; When the detected temperature interval of the temperature distribution layer along the thickness direction in the thermal insulation layer (2) is ≤600K, a first heat pipe (41) is arranged in the temperature distribution layer corresponding to the temperature interval ≤600K.

20. The heat pipe assisted cooling method for a graphitization furnace according to claim 19, characterized in that: The first heat pipe (41), the second heat pipe (42) and the third heat pipe (43) are arranged at an angle of 15° to 60° on the horizontal surface of the thermal insulation layer (2).

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